1. Technical Field
The present disclosure generally relates to valve actuator assemblies, more particularly, to valve actuator assemblies for use in a marine environment and methods of using the same.
2. Description of the Related Art
Valve actuators are often used to open and close valves positioned along pipes. Electric valve actuators can be used in a wide range of settings, including in waste water treatment plants, refineries, power plants, factories, and transportation vehicles, such as watercraft. Based on the ambient environment, components of electric valve actuators can be corrosion resistant, temperature resistant, explosion resistant, and/or resistant to other environmental conditions.
Electric valve actuators often include an electric motor and a rotatable hand wheel assembly that can operate independently of the electric motor. When the motor is energized, the valve actuator can automatically operate the valve. The hand wheel assembly may be inactive (i.e., the hand wheel assembly disengages a gear train for operating the valve) when the motor is energized. During a power failure or motor malfunction, an individual can rotate the hand wheel assembly to operate the valve. Thus, conventional electric valve actuators can manually or automatically operate the valve.
During operating, an electric valve actuator can limit or stop movement of a valve member (e.g., a gate) when the valve member reaches the end of travel position. At the end of travel of the valve member (e.g., when the valve is at or near the fully open or fully closed position), the force required to move the valve member may be relatively high. Torques required to move the valve members may therefore vary with respect to the position of the valve member. The valve actuators can have controllers that control actuation of the valve members. Because torque settings are not communicated between controllers, it is difficult to replace a controller and ensure proper functioning of the valve actuator without performing a calibration procedure involving applying a known calibrated load to the valve actuator. Unfortunately, conventional calibration procedures employ bulky, heavy calibration equipment that is often unsuitable for use in the field.
Valve actuators may have mechanical components used to determine the state of the valve (e.g., whether the valve is fully open, partially open, or fully closed). It may be difficult to calibrate these valve actuators because the mechanical components (e.g., components of mechanical sensors) may have to be replaced to adjust end of travel positions of the valve member, feedback, and the like. For example, helical springs of a mechanical sensor inside of a housing of conventional valve actuators may have to be replaced, thus requiring disassembling of the housing. When the housing is disassembled, unwanted contaminates (e.g., dirt or water) may enter the housing and cause impaired actuator performance, damage to the valve actuator, and the like.